Thanks for the KIP. I think the following is a little confusing since it doesn't make it clear the the ZooKeeper deployment is separate from Kafka, Kafka only includes the ZooKeeper libraries. I think it would be useful to explain the upgrade process for someone running Apache Kafka 2.3 and ZooKeeper 3.4 (the hardest case) and the same for someone running Apache Kafka 2.4 and ZooKeeper 3.5.
Also, it's worth clarifying that we actually still test direct kafka upgrades from 0.8.2 to 3.4. In practice, we have distinguished "providing updates" versus "allowing direct upgrades from". Apache Kafka 4.0 will change this since you will have to upgrade to a bridge release before upgrading to 4.0, but that's a new development. "Users who use Kafka clusters with Zookeeper clients older than 3.5.x won't be able to communicate with a Zookeeper cluster using 3.8.1. As mentioned in the accompanying JIRA ticket Apache Kafka has been using Zookeeper 3.5.x since version 2.4 so versions above and including it should be safe for this upgrade. It is acceptable to break compatibility with Apache Kafka versions prior to 2.4 as they are considered beyond their end of life and are not maintained. (source: Time Based Release Plan#WhatIsOurEOLPolicy)." Ismael On Wed, Feb 15, 2023 at 1:47 AM Christo Lolov <christolo...@gmail.com> wrote: > Hello! > > I would like to start a discussion for KIP-902: Upgrade Zookeeper to > 3.8.1. The Zookeeper version currently used in Kafka reached its end of > life in December 2022. You can find the KIP at > https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=240882784 > > Thanks in advance for the reviews. > > Christo
